After confirming he murdered Ms Vincent, who also used the name Bowring, the judge directed the jury to return a guilty verdict.

The jury had heard that Ms Vincent, who met Devine when they were both patients at the psychiatric unit at Ysbyty Glan Clwyd, Bodelwyddan, in October 2005, was stabbed at least five times with a serrated blade.

One stab wound penetrated eight inches into her abdomen piercing her liver and a kidney, the court heard.

Ms Vincent died on October 5, two days after she was attacked in Devine’s sister’s flat.

The court had heard she had become “strangely, deeply attracted” to Devine, and one of her relatives said she was “obsessed” with him.

Jurors also heard that before she died, Ms Vincent, was able to tell her ex-husband that it was Devine who had attacked her.

Before changing his evidence, Devine told the jury he had no idea what might have happened the night Ms Vincent was found stabbed.

He had agreed she had made sexual advances towards him while he was sending text messages to another woman.

Following the sentencing, Detective Inspector Steve Williams of North Wales Police said: “Our sympathies go to the family of Sandra Bowring. Christopher Devine was rightly convicted of the horrific attack, which resulted in the murder of Sandra.

“Throughout the investigation and even up until admitting his guilt he has shown no remorse for the offence.”